This paper presents the calculation of asymptotic directions of arrival of charged particles of the galactic cosmic rays (GCR) and the magnetic cutoff rigidity for the military airports in Dęblin ,Pruszcz Gdański, and Rzeszów -Jasionka based on numerical integration of the equations of the motion charged particles of the GCR in the Earth's magnetic field. The calculations were made for the International Geomagnetic Reference Field (IGRF) model from 2020. IGRF is an international and widely used mathematical model of the Earth's magnetic field. Each IGRF model is a set of spherical harmonics of degree n and of order m, representing the solution of Laplace's equation for the magnetic potential arising from sources inside the Earth in a given epoch.